Optoelectronic device with light-emitting diodes comprising at least one zener diode

Abstract

An optoelectronic device is provided, including light-emitting diodes arranged such that: N diodes of said plurality, where N ≥2, are connected in series and are configured to be forward-biased, and at least one diode is connected in parallel to the N diodes and is configured to be reverse-biased and to form a Zener diode, wherein a sum of threshold voltages of the N diodes is less than a breakdown voltage of the Zener diode, and the light-emitting diodes include a stack of semiconductive portions including a first conductivity-type doped portion, a second conductivity-type doped portion opposite the first type, and a first intermediate portion doped according to the first type and being disposed between said first and second portions and having a doping level such that the breakdown voltage is greater than the sum of the threshold voltages of each of the N diodes.

The invention claimed is: 
     
       1. An optoelectronic device, comprising:
 a plurality of light-emitting diodes, each exhibiting a threshold forward Voltage and a reverse breakdown voltage in a material comprising a same semiconductor compound, said plurality being arranged such that:
 N light-emitting diodes of said plurality, where N ≥2, are connected in series and are configured to be forward-biased, and 
 at least one light-emitting diode of said plurality is connected in parallel to the N light-emitting diodes and is configured to be reverse-biased and to form a Zener diode, 
 
 wherein a sum of threshold voltages of each of the N light-emitting diodes is less than a value of a breakdown voltage of the formed Zener diode, and 
 wherein the plurality of light-emitting diodes comprises a stack of semiconductive portions comprising a first portion doped according to a first type of conductivity, a second portion doped according to a second type of conductivity opposite to the first type, and a first intermediate portion doped according to the first type of conductivity, the first intermediate portion being disposed between said first and second portions and having a doping level such that the breakdown voltage is greater than the sum of the threshold voltages of each of the N light-emitting diodes. 
 
     
     
       2. The optoelectronic device according to  claim 1 , wherein the semiconductive portions of the stack are respectively coplanar and are a material of a same composition and having a same doping level. 
     
     
       3. The optoelectronic device according to  claim 2 , wherein the first intermediate portion has a nonzero thickness less than or equal to 5 nm. 
     
     
       4. The optoelectronic device according to  claim 1 , wherein the semiconductive portions of the stack further comprise a second intermediate portion doped according to the second type of conductivity, disposed between the first intermediate portion and the second portion, and having a doping level such that the breakdown voltage is greater than the sum of the threshold voltages of each of the N light-emitting diodes. 
     
     
       5. The optoelectronic device according to  claim 4 , wherein the semiconductive portions of the stack are respectively coplanar and are a material of a same composition and having a same doping level, and have a nonzero thick mess less than or equal to 50 nm. 
     
     
       6. The optoelectronic device according to  claim 1 , wherein the semiconductor compound is chosen from a III-V compound, a II-VI compound, and a IV element or compound. 
     
     
       7. The optoelectronic device according to  claim 1 , wherein the semiconductive portions of the stack further comprise an active layer disposed between said first and second portions, the stack forming a substantially coplanar mesa structure. 
     
     
       8. The optoelectronic device according to  claim 7 , wherein the first portion of said stack has a lateral flank comprising a setback surface formed by a second part of the first portion with respect to a first part thereof. 
     
     
       9. The optoelectronic device according to  claim 8 , further comprising a lateral electrical connection element extending at a level of the plurality of light-emitting diodes, being in electrical contact with the setback surface, being electrically insulated from an adjacent second portion of said stack and from an adjacent active portion of said stack by dielectric portions covering the lateral flank. 
     
     
       10. A method for producing the optoelectronic device according to  claim 1 , the method comprising:
 forming the plurality of light-emitting diodes in the material comprising the same semiconductor compound; 
 connecting in series the N light-emitting diodes of said plurality such that said diodes are configured to be forward-biased; and 
 connecting at least one light-emitting diode of said plurality in parallel to the N light-emitting diodes such that said at least one diode is configured to be reverse-biased and to form the Zener diode. 
 
     
     
       11. The method according to  claim 10 , wherein the step of forming comprises:
 producing a stack of layers comprising a first doped semiconductive layer and a second doped semiconductive layer between which is inserted an active layer; 
 etching the stack of layers, so as to form a first mesa structure to form the N light-emitting diodes, and so as to form a second mesa structure to form the Zener diode, each mesa structure being formed by a stack of a first doped portion, an active zone, and a second doped portion, the first doped portion of each of said mesa structures comprising a lateral flank having a setback surface; 
 producing dielectric portions covering the lateral flanks of said mesa structures except for the setback surfaces; and 
 depositing an electrically conductive material between said mesa structures, the electrically conductive material being in contact with the setback surfaces and being electrically insulated by the dielectric portions from the active zone and from the second doped portion. 
 
     
     
       12. The method according to  claim 11 , wherein the step of producing the stack of layers further comprises producing the first intermediate layer doped according to the first type of conductivity, disposed between the active layer and the second doped portion. 
     
     
       13. The method according to  claim 12 , wherein the step of producing the stack of layers further comprises producing the second intermediate layer doped according to the second type of conductivity, disposed between the first intermediate layer and the second doped portion. 
     
     
       14. The method according to  claim 12 , wherein a doping level of the first intermediate layer is adjusted such that the breakdown voltage of the formed Zener diode is less than the sum of the threshold voltages of said each of the N light-emitting diodes. 
     
     
       15. The method according to  claim 13 , wherein a doping level of the second intermediate layer is adjusted such that the breakdown voltage of the formed Zener diode is less than the sum of the threshold voltages of said each of the N light-emitting diodes. 
     
     
       16. The method according to  claim 11 , further comprising producing electrical connection elements configured to forward-bias the N light-emitting diodes and to reverse-bias the formed Zener diode through electrically conductive portions disposed facing the second doped portions.